Sound as an influencing factor on safe cycling

Agnieszka Stelling explores how sound impacts cyclist traffic safety. She will obtain her doctorate from TU Delft on Monday, 5 November 2018 with research into this subject. 

Many cases of serious injury
Cycling safety is an important aspect of traffic safety as a whole, both in the Netherlands and abroad. While the number of fatal cycling accidents may have decreased slightly within the European Union in recent years, this decrease is less pronounced than it is for fatal accidents involving those travelling in cars or pedestrians. In 2015, 20% of the total traffic-related fatalities and 63% of serious casualties in the Netherlands involved cyclists. 

Listening to music and phone use during cycling
The role played by sound represents a significant research theme within the field of cycling safety. Agnieszka Stelling looked at how sound impacts cyclists and their traffic safety in relation to (silent) electric cars, listening to music while cycling and making phone calls while cycling.
The research focused on cyclists in three age categories (16-18, 30-40 and 65-70 years old). Listening to music while cycling has a greater impact on how well cyclists hear other traffic than talking on the phone. The majority of the 16-year-old to 18-year-old age group (the group that most frequently uses their phone while cycling) indicated they could hear less ambient sound due to the music. Talking on the phone had less impact on what they could hear. 

Compensation strategies
The teenage respondents indicated that they resorted to compensation strategies when using their telephone while cycling. When listening to music, these strategies were: turning the music down or off, looking around more often or using one earphone instead of both. When talking on the phone, the teenagers most frequently reported reducing speed, keeping calls short and looking around more often. ‘However, observation research in traffic revealed that the extent to which cyclists better observed their surroundings was negligible’, says Stelling. So negligible in fact, that this research component was ended prematurely to prevent undue exposure to hazardous situations’.   

Electric cars: adding sound not necessarily the solution
Another aspect of the research concerns electric cars. These cars prove more difficult to localise than conventional cars, especially when travelling at low speed. Localisation is also more difficult if the sound comes from directly behind the listener. When asked to localise sounds in a laboratory setting, particularly the older age groups had difficulty localising the sound of cars, either conventional or electric.
Stelling suggests that it remains to be seen whether adding artificial sound to electric cars is a viable solution. ‘It is likely that the added sound is masked by ambient noise to such an extent that the ultimate effect is minimal’.

More information
Karlijn Spoor, Communications adviser Civil Engineering & Geosciences TU Delft, +31 15 2789885, K.Spoor@tudelft.nl